Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.139
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Environ Res ; 243: 117871, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38086499

RESUMO

This work proposes a rigorous mathematical model capable of reproducing the adsorption process in dynamic regime on advanced monoliths geometries. For this, four bed geometries with axisymmetric distribution of channels and similar solid mass were proposed. In each geometry a different distribution of channels was suggested, maintaining constant the bed dimensions of 15 cm high and 5 cm radius. The mathematical modeling includes mass and momentum transfer phenomena, and it was solved with the COMSOL Multiphysics software using mass transfer parameters published in the literature. The overall performance of the column was evaluated in terms of breakthrough (CA/CA0 = 0.1) and saturation times (CA/CA0 = 0.9). The mass and velocity distributions obtained from the proposed model show good physical consistency with what is expected in real systems. In addition, the model proved to be easy to solve given the short convergence times required (2-4 h). Modifications were made to the bed geometry to achieve a better use of the adsorbent material which reached up to 80%. The proposed bed geometries allow obtaining different mixing distributions, in such a way that inside the bed a thinning of the boundary layer is caused, thus reducing diffusive effects at the adsorbent solid-fluid interface, given dissipation rates of about 323 × 10-11 m2/s3. The bed geometry composed of intersecting rings deployed the best performance in terms of usage of the material adsorbent, and acceptable hydrodynamical behavior inside the channels (maximum fluid velocity = 35.4 × 10-5 m/s and drop pressure = 0.19 Pa). Based on these results, it was found that it is possible to reduce diffusional effects and delimit the mass transfer zone inside the monoliths, thus increasing the efficiency of adsorbent fixed beds.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Purificação da Água , Adsorção , Modelos Teóricos , Matemática , Difusão
2.
Exp Brain Res ; 241(2): 417-425, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36571635

RESUMO

Intermittent ethanol consumption changes the neuronal activity of the orbitofrontal cortex (OFC) in rodents, which has been attributed to important participation in the development of addiction, particularly alcoholism. The OFC participates in gustatory sensory integration. However, it is unknown whether this region can encode chemosensory elements of oral ethanol administration independently of the consumption movement (orofacial motor response) when administered for the first time (naïve mice). To answer this question, we used a sedated mouse model and a temporary analysis protocol to register extracellular neuronal responses during the oral administration of ethanol. Our results show an increase in neuronal frequency (in the first 500 ms) when low (0.6, 1, and 2.1 M) and high (3.2, 4.3, and 8.6 M) concentrations of ethanol are orally administered. The modulatory effect of ethanol was observed from low and high concentrations and differed from the tastants. There was consistent neuronal activity independent of the concentration of ethanol. Our results demonstrate a sensory representation of oral ethanol stimulation in the OFC neurons of naïve mice under sedation.


Assuntos
Alcoolismo , Etanol , Camundongos , Animais , Etanol/farmacologia , Córtex Pré-Frontal/fisiologia , Neurônios/fisiologia , Sensação
3.
J Assist Reprod Genet ; 40(7): 1755-1763, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37171739

RESUMO

PURPOSE: To identify novel genetic variants responsible for meiotic embryonic aneuploidy. METHODS: A prospective observational cohort study that included 29 couples who underwent trophectoderm biopsies from 127 embryos and performed whole-exome sequencing (WES) between November 2019 and March 2022. Patients were divided into two groups according to the expected embryo aneuploidy rate based on maternal age. RESULTS: After variant filtering in the WES analysis of 58 patients/donors, five heterozygous variants were identified in female partners from the study group that had an impact on embryo aneuploidy. Additionally, a slowdown in embryo development and a decrease in the number of blastocysts available for biopsy were observed in the study group embryos. CONCLUSION: This study has identified new candidate genes and variants not previously associated with meiotic embryo aneuploidy, but which are involved in important biological processes related to cell division and chromosome segregation. WES may be an efficient tool to identify patients with a higher-than-expected risk of embryo aneuploidy based on maternal age and allow for individualized genetic counselling prior to treatment.


Assuntos
Diagnóstico Pré-Implantação , Gravidez , Humanos , Feminino , Estudos Prospectivos , Sequenciamento do Exoma , Aneuploidia , Idade Materna , Blastocisto , Testes Genéticos
4.
Phys Chem Chem Phys ; 24(23): 14440-14451, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35662295

RESUMO

We report a computational study of the structural and energetic properties of water clusters and singly-charged water cluster anions containing from 20 to 573 water molecules. We have used both a classical and a quantum description of the molecular degrees of freedom. Water intra and inter-molecular interactions have been modelled through the SPC/F model, while the water-excess electron interaction has been described via the well-known Turi-Borgis potential. We find that in general the quantum effects of the water degrees of freedom are small, but they do influence the cluster-size at which the excess electron stabilises inside the cluster, which occurs at smaller cluster sizes when quantum effects are taken into consideration.

5.
Dis Aquat Organ ; 150: 69-83, 2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35833546

RESUMO

Marine mammals, regarded as sentinels of aquatic ecosystem health, are exposed to different pathogens and parasites under natural conditions. We surveyed live South American fur seals Arctocephalus australis and South American sea lions Otaria flavescens in Uruguay for Leptospira spp., canine distemper virus (CDV), Mycobacterium spp., Toxoplasma gondii, and Neospora caninum. Samples were collected from 2007 to 2013. The seroprevalence of Leptospira spp. was 37.6% positive, 50.9% negative, and 11.5% suspect for A. australis (n = 61) while for O. flavescens (n = 12) it was 67% positive, 25% negative, and 8% suspect. CDV RNA was not detected in any of the analyzed samples. Most animals tested seropositive to tuberculosis antigens by WiZo ELISA (A. australis: 29/30; O. flavescens: 20/20); reactivity varied with a novel ELISA test (antigens MPB70, MPB83, ESAT6 and MPB59). Seroprevalence against N. caninum and T. gondii was 6.7 and 13.3% positive for O. flavescens and 0 and 2.2% positive for A. australis respectively. To evaluate possible sources of infection for pinnipeds, wild rats Rattus rattus and semi-feral cats Felis catus were also tested for Leptospira spp. and T. gondii respectively. Water samples tested for Leptospira revealed saprofitic L. bioflexa. Pathogenic Leptospira were detected in the kidneys of 2 rats, and cats tested positive for T. gondii (100%). These results represent a substantial contribution to the study of the health status of wild pinnipeds in Uruguay.


Assuntos
Caniformia , Doenças do Gato , Coccidiose , Otárias , Leptospira , Doenças dos Roedores , Toxoplasma , Toxoplasmose Animal , Animais , Animais Selvagens , Anticorpos Antiprotozoários , Gatos , Coccidiose/parasitologia , Coccidiose/veterinária , Ecossistema , Ratos , Estudos Soroepidemiológicos , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/parasitologia , Uruguai/epidemiologia
6.
Aesthetic Plast Surg ; 46(1): 258-264, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34351508

RESUMO

Liposuction remains one of the most frequently performed cosmetic surgical procedures and its popularity is increasing every year. However, since its inception, justified concerns regarding patient safety have placed limits on the volume of fat that can be aspirated, influenced by hemodynamic fluctuations and blood loss during liposuction. Tranexamic acid (TXA) is an antifibrinolytic agent that competitively inhibits the conversion of plasminogen to plasmin, thus preventing the binding and degradation of fibrin. Despite the existence of evidence of the effectiveness of TXA in orthopedic and cardiac surgeries, there is little evidence of its use in liposuction. The objective of this study was to evaluate the efficacy and safety of tranexamic acid in the control of surgical bleeding in patients undergoing liposuction, through a prospective, open, randomized and controlled clinical trial. Two groups of 25 participants each were formed to whom the application of TXA in a tumescent solution prior to liposuction or liposuction with the traditional technique was randomly assigned. The results showed a decrease in blood loss reflected by the differences in the final hematocrit values, as well as decrease in the same per aspirated volume (p = 0.003). No adverse events were found related with the TXA application and no blood transfusions were required in this group, in contrast to the control group where the need for blood transfusion was present in 20% of the intervened participants. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.


Assuntos
Lipectomia , Ácido Tranexâmico , Perda Sanguínea Cirúrgica/prevenção & controle , Humanos , Lipectomia/métodos , Estudos Prospectivos , Ácido Tranexâmico/uso terapêutico , Resultado do Tratamento
7.
J Helminthol ; 96: e46, 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35815391

RESUMO

To date, 34 species of the genus Homalometron (Apocreadiidae) have been described; five of them in Mexican fresh or brackish water fish, whereas five have been reported as parasites of members of the fish family Gerreidae. While sampling wildlife vertebrates during a field course of parasitology at the Los Tuxtlas Biological Station (Instituto de Biología, Universidad Nacional Autónoma de México) in Veracruz, specimens of digeneans were collected from the intestine of the stripped mojarra, Eugerres plumeri in Sontecomapan Lagoon. Specimens were studied morphologically and molecularly, and we discovered that they represented a new species of Homalometron. The new species is morphologically like the other four congeners in having three pairs of well-developed oral papillae on the oral sucker: Homalometron elongatum; Homalometron lesliorum; Homalometron carapavae; and Homalometron papilliferum. Here, we describe the newly discovered species, increasing our understanding about the parasite diversity of brackish water fishes of Mexico.


Assuntos
Doenças dos Peixes , Parasitos , Perciformes , Trematódeos , Animais , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Golfo do México , México , Perciformes/parasitologia
8.
Pflugers Arch ; 473(3): 317-329, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33398498

RESUMO

In cardiac muscle, the process of excitation-contraction coupling (ECC) describes the chain of events that links action potential induced myocyte membrane depolarization, surface membrane ion channel activation, triggering of Ca2+ induced Ca2+ release from the sarcoplasmic reticulum (SR) Ca2+ store to activation of the contractile machinery that is ultimately responsible for the pump function of the heart. Here we review similarities and differences of structural and functional attributes of ECC between atrial and ventricular tissue. We explore a novel "fire-diffuse-uptake-fire" paradigm of atrial ECC and Ca2+ release that assigns a novel role to the SR SERCA pump and involves a concerted "tandem" activation of the ryanodine receptor Ca2+ release channel by cytosolic and luminal Ca2+. We discuss the contribution of the inositol 1,4,5-trisphosphate (IP3) receptor Ca2+ release channel as an auxiliary pathway to Ca2+ signaling, and we review IP3 receptor-induced Ca2+ release involvement in beat-to-beat ECC, nuclear Ca2+ signaling, and arrhythmogenesis. Finally, we explore the topic of electromechanical and Ca2+ alternans and its ramifications for atrial arrhythmia.


Assuntos
Função Atrial/fisiologia , Acoplamento Excitação-Contração/fisiologia , Contração Miocárdica/fisiologia , Miócitos Cardíacos/metabolismo , Animais , Humanos
9.
Phys Rev Lett ; 126(17): 175502, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33988423

RESUMO

We report the first study on the thermal behavior of the stiffness of individual carbon nanotubes, which is achieved by measuring the resonance frequency of their fundamental mechanical bending modes. We observe a reduction of the Young's modulus over a large temperature range with a slope -(173±65) ppm/K in its relative shift. These findings are reproduced by two different theoretical models based on the thermal dynamics of the lattice. These results reveal how the measured fundamental bending modes depend on the phonons in the nanotube via the Young's modulus. An alternative description based on the coupling between the measured mechanical modes and the phonon thermal bath in the Akhiezer limit is discussed.

10.
Exp Brain Res ; 239(8): 2375-2397, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34101000

RESUMO

A previous study has indicated that during the state of central sensitization induced by the intradermic injection of capsaicin, there is a gradual facilitation of the dorsal horn neuronal responses produced by stimulation of the high-threshold articular afferents that is counteracted by a concurrent increase of descending inhibitory actions. Since these changes occurred without significantly affecting the responses produced by stimulation of the low-threshold articular afferents, it was suggested that the capsaicin-induced descending inhibition included a preferential presynaptic modulation of the synaptic efficacy of the slow conducting nociceptive joint afferents (Ramírez-Morales et al., Exp Brain Res 237:1629-1641, 2019). The present study was aimed to investigate more directly the contribution of presynaptic mechanisms in this descending control. We found that in the barbiturate anesthetized cat, stimulation of the high-threshold myelinated afferents in the posterior articular nerve (PAN) produces primary afferent hyperpolarization (PAH) in the slow conducting (25-35 m/s) and primary afferent depolarization (PAD) in the fast conducting (40-50 m/s) articular fibers. During the state of central sensitization induced by capsaicin, there is a supraspinally mediated shift of the autogenic PAH to PAD that takes place in the slow conducting fibers, basically without affecting the autogenic PAD generated in the fast conducting afferents. It is suggested that the change of presynaptic facilitation to presynaptic inhibition induced by capsaicin on the slow articular afferents is part of an homeostatic process aimed to keep the nociceptive-induced neuronal activity within manageable limits while preserving the proprioceptive information required for proper control of movement.


Assuntos
Nociceptividade , Células do Corno Posterior , Animais , Capsaicina/farmacologia , Gatos , Estimulação Elétrica , Neurônios Aferentes , Nociceptores , Propriocepção , Medula Espinal
11.
J Eur Acad Dermatol Venereol ; 35(2): 403-410, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32455486

RESUMO

BACKGROUND: MC1R polymorphisms interact with CDKN2A mutations modulating melanoma risk and contribute to a less suspicious clinical and dermoscopic appearance of melanomas. Different strategies, including dermoscopic comparative approach and digital monitoring, are used for the melanoma diagnosis in this context. OBJECTIVE: To analyse the diagnostic accuracy of the morphologic approach and comparative approach in dermoscopy, and to detect melanoma in familial melanoma (FamMM) patients according to different genetic backgrounds. METHODS: Two independent readers evaluated 415 lesions belonging to 25 FamMM: 26 melanomas (62% in situ, 36% early invasive) and 389 naevi, blinded for dermoscopic and histopathologic diagnosis, following two different steps. First step-Randomized: all lesions were randomly located in one single folder. Second step-Comparative approach: the lesions were clustered by patient. Sensitivity, specificity and number needed to excise (NNE) for melanoma diagnosis were calculated for both diagnostic strategies. Sensitivity and specificity were also assessed regarding the genetic background. RESULTS: The comparative approach showed lower sensitivity compared to the morphologic approach (69.2 and 73.1 vs. 76.9 both readers) but better specificity (95.9 and 95.1 vs. 84.3 and 90.2, respectively). NNE was better in the comparative approach. The readers had more difficulties diagnosing lesions from CDKN2A mutation carriers with red hair colour (RHC) MC1R variants. CONCLUSION: The comparative approach can be useful in high-risk patients to decrease the NNE. Early melanomas in CDKN2A carriers with RHC polymorphisms are more difficult to diagnose even with the comparative approach and benefit from the detection of changes during digital dermoscopy monitoring for early diagnosis.


Assuntos
Melanoma , Neoplasias Cutâneas , Dermoscopia , Diagnóstico Precoce , Genótipo , Humanos , Melanoma/diagnóstico , Melanoma/genética , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/genética
12.
Am J Physiol Heart Circ Physiol ; 318(5): H1245-H1255, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32275472

RESUMO

Carvedilol is an FDA-approved ß-blocker commonly used for treatment of high blood pressure, congestive heart failure, and cardiac tachyarrhythmias, including atrial fibrillation. We investigated at the cellular level the mechanisms through which carvedilol interferes with sarcoplasmic reticulum (SR) Ca2+ release during excitation-contraction coupling (ECC) in single rabbit atrial myocytes. Carvedilol caused concentration-dependent (1-10 µM) failure of SR Ca2+ release. Failure of ECC and Ca2+ release was the result of dose-dependent inhibition of voltage-gated Na+ (INa) and L-type Ca2+ (ICa) currents that are responsible for the rapid depolarization phase of the cardiac action potential (AP) and the initiation of Ca2+-induced Ca2+ release from the SR, respectively. Carvedilol (1 µM) led to AP duration shortening, AP failures, and peak INa inhibition by ~80%, whereas ICa was not markedly affected. Carvedilol (10 µM) blocked INa almost completely and reduced ICa by ~40%. No effect on Ca2+-transient amplitude, ICa, and INa was observed in control experiments with the ß-blocker metoprolol, suggesting that the carvedilol effect on ECC is unlikely the result of its ß-blocking property. The effects of carvedilol (1 µM) on subcellular SR Ca2+ release was spatially inhomogeneous, where a selective inhibition of peripheral subsarcolemmal Ca2+ release from the junctional SR accounted for the cell-averaged reduction in Ca2+-transient amplitude. Furthermore, carvedilol significantly reduced the probability of spontaneous arrhythmogenic Ca2+ waves without changes of SR Ca2+ load. The data suggest a profound antiarrhythmic action of carvedilol in atrial myocytes resulting from an inhibitory effect on the SR Ca2+ release channel.NEW & NOTEWORTHY Here we show that the clinically widely used ß-blocker carvedilol has profound effects on Ca2+ signaling and ion currents, but also antiarrhythmic effects in adult atrial myocytes. Carvedilol inhibits sodium and calcium currents and leads to failure of ECC but also prevents spontaneous Ca2+ release from cellular sarcoplasmic reticulum (SR) Ca2+ stores in form of arrhythmogenic Ca2+ waves. The antiarrhythmic effect occurs by carvedilol acting directly on the SR ryanodine receptor Ca2+ release channel.


Assuntos
Potenciais de Ação , Antagonistas Adrenérgicos beta/farmacologia , Sinalização do Cálcio , Carvedilol/farmacologia , Acoplamento Excitação-Contração , Miócitos Cardíacos/efeitos dos fármacos , Animais , Células Cultivadas , Masculino , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/fisiologia , Coelhos
13.
Opt Lett ; 45(22): 6170-6173, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-33186942

RESUMO

We report on continuous-wave laser operation of Tb3+:LiLuF4 under UV pumping. More than five times higher absorption cross sections in the UV allow for shorter gain media, which are required for future high-power diode pumping. The cross-relaxation process is found to efficiently populate the upper laser level 5D4 at doping concentrations typically used in Tb3+-doped gain media. Pumping with a frequency doubled Ti:sapphire laser at 359 nm enables laser operation in the green and yellow spectral range with slope efficiencies of 41% and 20%, respectively, at optical-to-optical efficiencies a factor of two higher than under cyan-blue pumping.

14.
Appl Opt ; 59(20): 6131-6137, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32672760

RESUMO

An adaptive optical fiber sensor/demodulator of an optical phase modulation with a Sagnac interferometer configuration is reported. The dynamic population grating recorded in ytterbium-doped fiber (YDF) at a wavelength of 1064 nm enables adaptive properties of this configuration with a high-pass transfer function and with the cut-off frequency of about 260 Hz at ∼10mW cw recording power. A linear response with nearly 100% modulation depth is ensured by effective formation of the nonshifted phase dynamic grating with the amplitude one order of magnitude greater than can be expected from the saturation of the YDF absorption at the recording wavelength. This is associated with the photoinduced changes in the UV optical absorption of the YDF and enables minimal detected amplitude of the phase modulation ≈0.7∗10-7Hz in our experimental configuration. We believe that, in general, this mechanism of the phase grating formation can ensure the sensor resolution limited by the photonic noise of the utilized light power only.

15.
Matern Child Health J ; 24(10): 1308-1317, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32557133

RESUMO

OBJECTIVES: Despite health risks for themselves and their children, urban underserved women smoke at high rates postpartum. The postpartum period is a stressful transition time that presents unique barriers to sustained cessation. There is limited extant evidence of efficacious psychosocial programs to maintain postpartum smoking cessation. METHODS: Guided by the Cognitive-Social Health Information Processing model, we explored the feasibility of TxT2Commit, a text-messaging intervention designed to prevent postpartum smoking relapse. Participants (n = 43) received supportive cessation-focused text messages for one month postpartum. Using a convergent mixed method design, surveys and interviews assessed changes in psychosocial factors and smoking status through a three month follow-up. RESULTS: Participants reported satisfaction with TxT2Commit, rating text messages as helpful, understandable, supportive, and not bothersome. However, a majority of women (n = 28, 65.1%) relapsed by three months. Participants who stayed smoke free (i.e., non-relapsers) reported significantly less temptation to smoke at one and three months postpartum compared to relapsers (ps < .01). While relapsers had significantly less temptation at one month compared to baseline, temptation increased by three months (p < .01). Consistent with the quantitative results, qualitative interviews identified informational and coping needs, with continued temptation throughout the three months. Non-relapsers were able to manage temptation and reported greater support. CONCLUSIONS FOR PRACTICE: TxT2Commit demonstrates preliminary feasibility and acceptability among urban, underserved postpartum women. However, most participants relapsed by three months postpartum. Additional research is needed to identify targeted messaging to best help women avoid temptation and bolster support to stay smoke free in this uniquely stressful period.


Assuntos
Disparidades em Assistência à Saúde/estatística & dados numéricos , Gestantes/psicologia , Fumantes/psicologia , Abandono do Hábito de Fumar/psicologia , Prevenção do Hábito de Fumar/métodos , Envio de Mensagens de Texto/estatística & dados numéricos , Adulto , Estudos de Viabilidade , Feminino , Promoção da Saúde/métodos , Humanos , Entrevistas como Assunto , Pennsylvania , Período Pós-Parto , Pesquisa Qualitativa , Abandono do Hábito de Fumar/métodos , População Urbana , Populações Vulneráveis
16.
Allergol Immunopathol (Madr) ; 48(6): 612-618, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32446784

RESUMO

BACKGROUND: The chemical modification of allergens with glutaraldehyde improves safety while maintaining clinical efficacy, which permits the administration of higher doses of immunotherapy, reducing the risk of adverse reactions. The aim of this study is to evaluate the immunogenic capacity of a new cat dander polymer by immunizing mice and quantifying immunoglobulins in serum, in comparison with the non-modified allergen. METHODS: The study consists of the immunization of three mice groups with the polymerized and the native extract, together with a negative control group. The immunoglobulin levels in serum have been measured by indirect ELISA. By means of the non-parametric Mann-Whitney U test, it was determined if there were significant differences in the values of specific antibodies between groups. RESULTS: The group immunized with the allergoid showed significantly higher specific IgG and IgG1 values to dander allergens and specific IgG to the major allergen Fel d 1, while there were no significant changes in IgG2a and IgE values. These results could be due to a higher immunization dose. The vaccine formulation was based on the optimal defined dose for clinical efficacy of allergen immunotherapy. CONCLUSIONS: This preclinical study carried out with the present assay has established that the allergoid of cat dander extract, as designed for its optimal use in allergen immunotherapy, produces a higher specific IgG than the native extract, in addition to showing significantly higher specific IgG1 levels, evidencing a greater effectiveness in immunization.


Assuntos
Alergoides/imunologia , Alérgenos Animais/imunologia , Dessensibilização Imunológica/métodos , Glicoproteínas/imunologia , Hipersensibilidade/terapia , Alergoides/administração & dosagem , Alergoides/química , Animais , Gatos , Alérgenos Animais/efeitos adversos , Modelos Animais de Doenças , Feminino , Humanos , Hipersensibilidade/sangue , Hipersensibilidade/imunologia , Imunogenicidade da Vacina , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Injeções Subcutâneas , Camundongos , Testes Cutâneos
17.
Exp Brain Res ; 237(7): 1629-1641, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30949729

RESUMO

Previous studies from our laboratory showed that in the anesthetized cat, the intradermal injection of capsaicin in the hindpaw facilitated the intraspinal field potentials (IFPs) evoked by stimulation of the intermediate and high-threshold myelinated fibers in the posterior articular nerve (PAN). The capsaicin-induced facilitation was significantly reduced 3-4 h after the injection, despite the persistence of hindpaw inflammation. Although this effect was attributed to an incremented descending inhibition acting on the spinal pathways, it was not clear if it was set in operation once the capsaicin-induced effects exceeded a certain threshold, or if it was continuously operating to keep the increased neuronal activation within manageable limits. To evaluate the changes in descending inhibition, we now examined the effects of successive reversible spinal blocks on the amplitude of the PAN IFPs evoked at different times after the intradermal injection of capsaicin. We found that after capsaicin the PAN IFPs recorded in laminae III-V by activation of high-threshold nociceptive Aδ myelinated fibers increased gradually during successive reversible spinal blocks, while the IFPs evoked by intermediate and low threshold proprioceptive Aß afferents were only slightly affected. It is concluded that during the development of the central sensitization produced by capsaicin, there is a gradual increase of descending inhibition that tends to limit the nociceptive-induced facilitation, mainly by acting on the neuronal populations receiving inputs from the capsaicin-activated afferents without significantly affecting the information on joint angle transmitted by the low threshold afferents.


Assuntos
Capsaicina/farmacologia , Neurônios Aferentes/efeitos dos fármacos , Nociceptores/efeitos dos fármacos , Células do Corno Posterior/efeitos dos fármacos , Tratos Piramidais/efeitos dos fármacos , Fármacos do Sistema Sensorial/farmacologia , Animais , Gatos , Feminino , Masculino , Neurônios Aferentes/fisiologia , Nociceptores/fisiologia , Células do Corno Posterior/fisiologia , Tratos Piramidais/fisiologia
18.
Appl Opt ; 58(24): 6495-6503, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31503577

RESUMO

Application of the phase memory of acetylene (C2H2) vibrational-rotational transitions in the 1520-1540 nm wavelength range for a self-referencing homodyne detection of a sub-nanosecond optical phase modulation is reported. In the proposed configuration the collinearly propagating coherent dipole radiation of the excited molecule acts like a phase-locked reference wave (local oscillator) that enables transformation of the initial phase modulation into the intensity one. This technique does not need high light intensity and can operate in a linear range of the medium optical absorption. The linear optical phase demodulation (i.e., transformation of the phase-to-amplitude light modulation) is interpreted as an introduction of an additional phase shift to the carrier frequency component of the modulated signal in the maximum of the dispersion curve of a narrow optical absorption peak. It has been experimentally demonstrated with the bulk 10 cm long cuvette filled with low pressure (∼2 Torr) acetylene at room temperature. Effective demodulation of the milliwatt-scale incident laser wave of a single- and multi-mode structure is shown. As expected, the response to the fast (<1 ns) phase modulation was quadratic when the acetylene inhomogeneous Doppler-broadened (∼500 MHz) absorption line is excited in its center and was linearized by tuning at one of the absorption line sides. It is of a differentiating (high-pass) type with the cutoff frequency determined by the total spectral width of the utilized absorption line. Expected detection resolution is determined by the photon noise of the incident light intensity.

20.
Bull Entomol Res ; 109(3): 333-341, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30032728

RESUMO

The control of Anastrepha obliqua includes the sterilization of mass-reared insects grown in isolation in a constantly controlled environment. Through time, laboratory mass-reared colonies may produce flies with lower field performance. To recover the genetic variation and aptitude of mass-reared populations, wild insects are introduced into mass-reared colonies. Our aim in this study was to determine whether the host species from two localities influence the life history traits of A. obliqua. We collected flies as larvae from infested fruits of Spondias purpurea, S. mombin, Mangifera indica cv. 'piña', and M. indica cv. 'coche' from two localities in Chiapas, Mexico. There were significant differences in the mating competitiveness of males collected from mango cv. 'coche' compared with mass-reared males. There were no differences in the mating propensity between flies from the two localities, even in the number of matings, when weight was considered as a covariable. The mass-reared strain showed the earliest age at first oviposition. The locality affected the longevity and oviposition period, and these influenced the birth rate, intrinsic rate of increase, finite rate of population increase, mean generation time, and doubling time. According to the demographic parameters, the population of S. mombin would allow artificial colonization in less time, considering that it has a high reproduction rate starting at an early age. Even in the propensity test, it had the highest number of matings. However, males with greater sexual competitiveness and longevity for colonization corresponded to those collected from S. purpurea.


Assuntos
Frutas , Comportamento Sexual Animal , Tephritidae/fisiologia , Anacardiaceae , Criação de Animais Domésticos , Animais , Dieta , Feminino , Estágios do Ciclo de Vida/fisiologia , Longevidade , Masculino , Mangifera , México , Oviposição/fisiologia , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA